AD 2020-23-03 Was Prompted By The Development Of The MOD By Airbus Helicopters That Addresses The Unsafe Condition

The FAA is superseding Airworthiness Directive (AD) 2017-09-05 for Airbus Helicopters Model AS332C, AS332C1, AS332L, AS332L1, AS332L2, and EC225LP helicopters. AD 2017-09-05 required repetitively checking screws in the emergency flotation gear.

This new AD retains the requirements of AD 2017-09-05 but also requires installing a modification (MOD), which is a terminating action for the repetitive checks. This AD was prompted by the development of the MOD by Airbus Helicopters that addresses the unsafe condition. The actions of this AD are intended to address an unsafe condition on these products. This AD is effective January 4, 2021.

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to remove AD 2017-09-05, Amendment 39-18867 (82 FR 21913, May 11, 2017) (“AD 2017-09-05”), and add a new AD. AD 2017-09-05 applied to Airbus Helicopters Model AS332C, AS332C1, AS332L, AS332L1, AS332L2, and EC225LP helicopters with emergency flotation gear installed. The NPRM published in the Federal Register on August 7, 2020 (85 FR 47921). The NPRM proposed to require, within 15 hours time-in-service (TIS) and thereafter, before each flight over water,  visually checking each emergency flotation gear left-hand (LH) and right-hand (RH) rear upper fitting for the presence of screw heads and looseness. An owner/operator (pilot) may perform the required visual check but must enter compliance with the applicable paragraph of this AD in the helicopter maintenance records in accordance with 14 CFR 43.9(a)(1) through (4) and 91.417(a)(2)(v). A pilot may perform this check because it involves visually checking the rear upper fittings of the LH and RH emergency flotation gears for the presence of screw heads and twisting the screws by hand. This action can be performed equally well by a pilot or a mechanic. This check is an exception to the FAA's standard maintenance regulations. If any screws are loose or any screw heads are missing, the NPRM proposed to require removing from service the screws on each LH and RH side on the flotation gear rear fitting and installing MOD 0728456, base washers and spherical washers. The NPRM also proposed to require, within 300 hours TIS, installing MOD 0728456 as a terminating action for the repetitive checks.

AD 2017-09-05 was prompted by EASA AD 2015-0239-E, dated December 18, 2015 (EASA AD 2015-0239-E), issued by EASA, which is the Technical Agent for the Member States of the European Union, to correct an unsafe condition for Airbus Helicopters Model AS332C, AS332C1, AS332L, AS332L1, AS332L2, and EC225LP helicopters. EASA advised that a screw ruptured on the rear upper fitting on the LH emergency flotation gear of an AS332 helicopter. EASA stated that this condition, if not detected and corrected, could result in the failure of an emergency flotation system when ditching and unstable floating of the helicopter, possibly resulting in injuries to the occupants. The EASA AD consequently required repetitive inspections of the lower attachment screws of rear upper fitting on the rear LH and RH emergency flotation gears. EASA stated that the root cause of the failure had not yet been identified.

After the FAA issued AD 2017-09-05, Airbus Helicopters identified the root cause of the screw rupture as a tapering gap under the fitting attachment screw heads creating excessive stress loads. Consequently, EASA issued AD No. 2018-0090, dated April 20, 2018 (EASA AD 2018-0090), to supersede EASA AD 2015-0239-E. EASA AD 2018-0090 retains the repetitive inspection requirements in EASA AD 2015-0239-E and also requires the installation of Airbus Helicopters MOD 0728456 as a terminating action for the repetitive inspections. MOD 0728456 involves the installation of spherical washers and longer screws on the rear upper fittings of the flotation gear to remove the stress applied to the screw heads.

FMI: www.regulations.gov